JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input id="toggleDisabled" type="button" value="Enable send" />
    
<input id="sendInvite" class="mail_send" disabled="disabled" type="button" name="invite" value="Send" />
</form>

CSS

.mail_send:disabled {background-color:#343434; color:#747474}

JavaScript

$("#toggleDisabled").click(function() {
    if ($("#sendInvite").is(":disabled")) 
    {
        $("#toggleDisabled").val("Disable send");
        $("#sendInvite").prop("disabled", false);
    } 
    else 
    {
        $("#toggleDisabled").val("Enable send");
        $("#sendInvite").prop("disabled", "disabled");
    }
});